This invention relates broadly to wind operated musical instruments and particularly to those musical instruments which are resonant in response to vibrating air columns induced therein to produce tones of various different pitches.
Conventional wind instruments may be categorized in accordance with the manner in which a vibrating air column is induced in them. Thus, there are lip reed instruments, examples of which include trumpets, cornets, trombones, french horns, and bass horns; reed instruments, examples of which include clarinets, saxophones, oboes, and bassoons; and split-air-stream instruments, examples of which include piccolos and flutes.
In each of the above-mentioned instruments, as well as in many other instruments, sound vibrations are created at an inlet or mouthpiece and these sound vibrations are channeled through an elongated instrument tube whose effective length is configured, that is lengthened or shortened, to create resonance therein so as to amplify the sound vibrations and promulgate them to the surrounding area. The original sound vibrations at the mouthpiece are created in different ways for different instruments. For the lip reed instruments, the vibrations are created by vibrating lips whereas for the reed instruments the vibrations are caused by single or double reeds. For the split-air-stream instruments, air is caused to vibrate by passing over air-splitting baffle edges. In each of these instruments, a musician can control these initial vibrations with mouth activity by controlling the quantity, velocity and/or direction of air flow, by the position of the lips, etc. By using mouth control, a musician can control to a great extent musical sounds which exit from a musical wind instrument, and in this regard, some instruments, such as a bugle, are played totally by mouth control. However, mouth control related to a single effective air column length is somewhat limited and does not allow a full range of musical notes.
The frequencies of the vibrations at which an instrument is resonant depend upon the length of the instrument, that is, the length of the tube between its air inlet and its air outlet. This length determines, but is not quite equal to, the effective length of the air column in which the sound waves are formed that, at certain frequencies, cause the instrument to resonate and thereby amplify the sound output of the instrument. It is well known that, to resonate at any given frequency, an instrument must have an effective air column equal in length to an integer multiple of one-half of the wave length of that frequency. This forms the basis for the so-called "harmonic series" of notes that can be resonant and amplified by an instrument having an air column of a given effective length, which series may be expressed by the series of fractions 1/2, 2/2, 3/2, 4/2 . . . n/2, wherein the numerator represents the number of one-half waves formed in the air column.
The common bugle has a single fixed length and is therefore capable of resonating only at frequencies within a single harmonic series. It cannot be used to produce a complete major or minor scale. In order to extend the range of the several instruments mentioned above, so that they may be used to produce not only major and minor scales but also complete chromatic scales, the instruments are provided with mechanisms to change the tube and effective air column lengths. Such mechanisms usually comprise telescoping slides, openable ports, or depressible or rotatable valve keys to provide openings to differing combinations of tubing sections. Because of the ability to change the effective air column lengths, the instruments can be used to produce multiple sets of harmonic series and thereby to produce complete chromatic scales.
The frequency, and therefore the pitch, of vibration of a wind instrument depends upon the frequency of the input to instrument. Typically, a wind instrument, including its mouthpiece, is so constructed that one may produce frequencies beginning with the first or second harmonic number and, depending upon the skill of the musician, extending upwardly through several harmonic numbers. One may change the inlet openings so that the frequencies produced tend to be in the higher harmonic ranges. For example, an instrument made by equipping a bass horn with a conventional trumpet mouthpiece may not be usable to play the lower harmonics but could be used for playing higher harmonics than can be obtained using a conventional bass horn mouthpiece. This is because the bass horn mouthpiece is designed to enable one to vibrate the lips at lower frequencies than possible with a trumpet mouthpiece, at the expense of higher frequencies available using a trumpet mouthpiece.
As those skilled in the art are aware, the number of scale notes between the members of a harmonic series decreases as the harmonic number increases. This phenomena is demonstrated by the following Table I, which is for a trombone having an effective air column length of 9.43 feet. (This Table I and Table II and Table III below are calculated using an assumed speed of sound of 1100 feet per second which is not quite accurate but is sufficient for purposes of understanding this invention.)
TABLE I ______________________________________ Harmonic Pitch Wave Length Scale Frequency ______________________________________ 2/2 A# 9.43 feet 116.54 cps B 123.41 C 130.81 C# 137.59 D 146.83 D# 155.56 E 164.81 3/2 F 6.29 174.61 F# 185.00 G 196.00 G# 207.65 A 220.00 4/2 A# 4.72 233.08 B 246.94 C 261.63 C# 277.18 5/2 D 3.78 293.66 D# 311.13 E 329.63 6/2 F 3.15 349.23 ______________________________________
One may observe that a trombone with an effective air column of 9.43 feet is capable of playing notes of ascending pitch in the sequence A#, F, A#, D, and F. Of course, a trombone usually has a slide for increasing the length of its effective air column so that other harmonic series can be formed. One may also observe from Table I that there are six scale notes between harmonic 2/2 and 3/2, four scale notes between harmonic 3/2 and 4/2, three scale notes between harmonic 4/2 and 5/2, and only two scale notes between 5/2 and 6/2. If the harmonic number is raised high enough, an instrument will play adjacent half tone notes. (At even higher harmonics, an instrument would play quarter tones.)
A problem with musical wind instruments capable of playing complete scales is that they require considerable skill, patience, and practice to play. Not only must musicians be dexterous with their fingers to reconfigure the instrument tubes, they must also memorize all of the proper positions and coordinate them with their lip movements.
An object of this invention to provide a musical wind instrument which may be used to play more notes than possible with a conventional instrument having a fixed tube length but which is simpler to play than conventional wind instruments having mechanisms for changing their tube lengths. More particularly, it is an object of this invention is provide a musical wind instrument which may be used to play a complete major scale without coordinated mouth and finger operations.
Another object of this invention is to provide a musical wind instrument which may be used to produce a complete chromatic scale with a minimum of coordinated mouth and finger operations.
Another object of this invention is to provide such a musical wind instrument which has a reasonably acceptable tone quality.
A musical wind instrument in accordance with one embodiment of this invention comprises a mouthpiece, an energy divider extending from the mouthpiece that divides the sound energy entering the mouthpiece into two or three streams, a tubing assembly for each of the streams connected to outlets from the energy divider, the tubing assemblies having open distal or free ends, one or all of which may terminate in bells. Each tubing assembly optionally and preferably includes a fixed-length body and a tuning slide. The different tubing assemblies are of respectively different lengths so that they resonate at different frequencies and thus may be used to produce more musical notes than possible with a single, fixed-length instrument.
In accordance with the presently preferred embodiment of this invention, the instrument is formed as two horns with a single inlet, with the length of one horn having a fundamental (harmonic 2/2) which is one half tone above the fundamental of the other horn. Other workable embodiments may have two horns having a difference in their respective fundamentals of two half tones. Still other embodiments may include a third horn having an inlet opening common with the other two horns, the third horn having a fundamental which is higher, again by one or two half tones, than the higher of the other two horns.
In a preferred practice of this invention, a mouthpiece is used which enables the two horns to be played without substantial difficulty in a range of frequencies beginning at the 4/2 harmonic and extending through the 12/2 harmonic. It will be demonstrated that such an instrument with two horns can play a complete major scale and several additional scale tones.
Further in accordance with embodiments of this invention, one or more of the plural horns is provided with one or more normally closed ports adjacent their distal or free ends.
Many combinations may be used to produce a musical wind instrument in accordance with this invention - either two or three horns, pitched one or two half tones apart, with no ports or with either one or two ports. Each combination would have its own set of advantages and disadvantages. The presently preferred embodiment of this invention comprises two horns of different length having a single, shared air inlet, the shorter horn having a fundamental that is one half tone higher than the longer horn, and the shorter horn having two ports spaced from its distal end by lengths such that the opening of the port nearest the distal end of the shorter horn will raise its fundamental by one half tone. The second port is used to adjust the pitch of certain scale notes and raise the fundamental of the shorter horn by an additional approximate half tone. However, the second port may optionally be omitted, particularly for the sake of simplicity, but with some loss of quality.
An important aspect of this invention is in connection with the energy divider. The divider has a single inlet branch opening to the mouthpiece and is split into either two or three outlet branches. It should be so constructed and located that the sound energy input provided by a musician playing the instrument is evenly divided as closely as practicable to the mouthpiece. Since the divider converts the single inlet branch into two or three outlet branches, it must necessarily expand in diameter and cross-sectional area. The expansion in cross-sectional area should be uniform and gradual.
In accordance with another embodiment of this invention, only one of the horns terminates in a bell. The other horn or horns could simply end, without expansion, as a tube. Also, optionally one horn could have conical tubing and the other horn or horns could have cylindrical tubing, or vice versa. In the case of a split-air-stream horn, all of the tubing sections could be cylindrical throughout their length. One caveat is that the frictional resistance to air being blown through each of the horns should be essentially equal; otherwise, the air will tend to follow the path with least resistance and provide inadequate sound energy to any horn having relatively greater air resistance.
Other objects and advantages will become apparent from the following description and the drawings.